The long-term goal of this project is to understand how the properties of dendrites and circuits influence the integration of pheromone-evoked activity in the mammalian accessory olfactory system. Integration of synaptic inputs arriving at thousands of sites across the dendritic tree is a basic mechanism that influences the functional properties of all neuronal types. In particular types of neurons the mechanisms of synaptic integration are thought to be highly specialized to process certain types of inputs, for example to detect short time delays in the auditory system. The dendritic trees of accessory olfactory bulb (AOB) mitral cells have a complicated and highly specialized morphology. These cells seem to be designed to sample inputs arriving at multiple locations (glomeruli), and then to convey some information about this activity to the mitral cell soma from which it can be passed on to higher brain areas. We propose to use physiological and computational techniques to improve our understanding of synaptic integration in the cells and circuits of the accessory olfactory bulb. In particular we will examine the influence of active and passive properties of AOB mitral cell dendrites on the propagation of synaptic activity from the tufts to the somata of these cells. We also will examine how inputs to multiple tufts are integrated, and determine how activity at one tuft is influenced by signals arriving at other tufts. Overall the experiments proposed will provide increased understanding of many basic issues of synaptic and dendritic processing in neurons, and in particular they will provide valuable information on the integration of chemosensory information in the accessory olfactory system. [unreadable] [unreadable]